Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

There are no annotations, so the description carries the full burden. It does disclose that the action stops all future executions immediately, which is a key behavioral trait. However, it omits potential side effects (e.g., whether the schedule is deleted, if it's reversible) and does not mention ownership verification requirements despite the agent_id parameter.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-structured sentence that front-loads the action. Every word contributes meaning, making it highly concise and easy to parse.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple cancellation tool, the description covers the core functionality and immediate effect. Given no output schema and no annotations, it could be more complete by mentioning ownership verification or behavior for inactive schedules, but it remains adequate for the tool's simplicity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, with both parameters already described (schedule_id as 'Schedule UUID to cancel' and agent_id as 'Agent ID for ownership verification'). The tool description adds no additional parameter meaning, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Cancel'), the resource ('an active cron schedule'), and the effect ('stop all future executions immediately'). This distinguishes it from sibling tools like schedule_task (create) and check_schedule (inspect), so the purpose is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies a clear use case: when you need to stop future executions of a schedule, use this tool. It doesn't explicitly mention alternatives or exclusions, but the context is clear enough that an agent can differentiate it from other schedule-related tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.